Primer and method of manufacture



Aug. 1,'1950 L.. 1'. MEISTER PRIMER AND METHOD oF MANUFACTURE Filed Nov. 9, 1945 f f IIIII.

LED T MEISTER,

Wfwfwm, @www Patented Aug. l, 1950 UNITED STATES PATENT OFFICE 2,516,893 PRIMER AND METHOD OF MAUFAOTURE Leo T. Meister, Irvington, N. J. Application November 9, 1945, Serial No. 627,770

(c1. srs- 20) (Granted under the act of March 3, 1883, as

amendedApril 30, 1928; 370 O. G. 757)` 17Claim.

The invention described herein may be manufactured and used by or for the Governmentl for governmental purposes without the payment to me of any royalty thereon.`

My invention relates to improvements in artillery ammunition primers, and in the method or process of manufacturing them.

`An important object of my invention is to provide an artillery ammunition primer in which the interior liner for the igniter charge tube containing the fiash or flame holes is formed of a fusible thin-walled metallic seamless tube closed at one end and all formed of one integral piece of metal, as for example, by a drawing operation. Closed and seamless tubes of the type referred to above resemble an elongated sewing thimble having fcylindricalwalls, and are referred to herein and in the appended claims as thimbles These thimbles may be made of any easily fusible suitable metal which is subject to plastic flow in drawing and which maybe easily creased or folded at the open end, and said folded end, upon the application of pressure, being capable of forming an effective seal against the harmful iniluence of air, gases and moisture as hereinafter more fully appears. Such thimbles may be advantageously formed of tin or lead, l

or alloys of tin and lead, said alloys consisting, for example, of 50% tin and 50% lead, or 60% lead and 40% tin. In the further description which follows, it may be assumed that these thimbles are made of, or drawn from an alloy of tin and lead, it being understood, however, that the naming of these metals and/or alloys is to be considered as words of inclusion and not of limitation, as will be understood by a person skilled in the art. Thimbles formed ofalloys of lead and tin have proved to be very satisfactory in the practice of the invention.

A further object of my invention is to provide an artillery primer in which a thimble liner as heretofore described may be closed and sealed against all harmful influence of air, gases and moisture without the use of an added sealing agent so that the primer, While simple in construction, will be eicient in operation.

Other objects and advantages of the invention will become apparent during the course of the following description.

The accompanying drawings, forming part of the specication, illustrate the manner in which I attain these objects. Similar numbers are used to designate like parts throughout the speciilcation and drawings. In these drawings:

Figure 1 is an elevation in perspective of one of the thimbles; l

Figure 2 is a longitudinal central section of an `igniter charge tube;`

Figures 3 to 6, inclusive, show longitudinal central sections of the igniter charge tube after the thimble has been positioned therein, and illustrate the successive steps bywhich the objects of the invention are attained;

Figure 3 shows the thimble in section in place within the tube; Y'

Figure 4 shows the thimble in section with the igniter charge in place within the thimble;

Figure 5 shows the thimble in elevation after mechanical or manual closing of the open end of the thimble;

Figure 6 shows an elevation of the closed thimble being forced against the igniter charge within the igniter charge tube;

Figure 7 is an elevation, partly in section, of an artillery ammunition primer manufactured according to the invention, including a'partial section of the head containing the cup for holding the usual percussion elements;

Figure 8 is an' elevation in perspective of a thimble containing an igniter charge as included in Figure 5 showing one method of closing the top by folding before forcing down against the igniter charge.

Referring now in detail to the accompanying drawings, the numeral I0 indicates a thin walled tin-lead alloy thimble as described and deiined above, the numeral II indicates an igniter charge tube, and numeral I2 indicates the head at the firing end of the tube II. Head I2 carries a suitable percussion element I2a for igniting the igniting charge hereinafter mentioned. Head I2 is attached to the igniter charge tube II by a portion of the former engaging with screw threads I3 within igniter tube II. The head I2 engages with the tube II tightly, and preferably tight enough that there is air tight engagement or connection between the -head I2 and the igniter tube II. As shown, igniter charge tube II is provided with a number of vents or ame holes I 4 for the passage of llame arising from the igniter charge when the primer is red. The igniter tube II is advantageously made of brass.

The thimble I0 is located within the igniter charge tube II. This thimble ts closely within the interior of the igniter charge tube II and covers all of the flame holes I4 thereof. The closed end of the thimble abuts against the closed end I5 of the igniter charge tube I I. The

thimble l0 is made long enough so that its open end will extend above the top of the igniter charge tube ll a distance suflicient to permit the walls of the open end to cover the entire opening when folded upon itself, and slightly smaller in diameter than the interior diameter of the igniter charge tube Il so that it may be inserted easily with a sliding t within igniter tube Il, and into the position shown in Figures 3 to 6, inclusive, so that the walls of the thimblei-r abut against the interior walls of the. igniter tube Il.

In loading the primer, a black powder charge or other igniter charge ll-` is inserted into the thimble IIJ after it has been inserted into position as shown in Figure 3, lling the said thimble I6 to the approximate level of the bottom of the screw threads I3, thus providing` an unlled air Tend has been pressed flat, or by any other method 4 y eifectivelyclosing the top of the thimble.

From' the foregoing it will be apparent that thethiinblev IQ may be formed of any metal that is readily fusible bythe heat or flame produced bythe burning ofthe igniter charge. There is, however, further advantages in using thimbles formed wholly or in'part of tin, or comprising space of the approximate heightof vthe distance" between the bottom of said screw threads i3 and the top of the tube H after the closing of the thimble l0. Thereupon, the walls of the open end are folded inwardly, ina manner similar to that used in closing the open end of a lled bag or package, using either mechanical or manual means, so that the now closedv top of the thimble Il) is approximately even with the open topv of the igniter tube Il, asshown in Figure 5. After the thimble I0 has been closed as'described above, the closed top and the `walls of the hollowl Aair space are pushed downward within the thimble l0 as shown in Figure 6, by either mechanical or manual means, against the top of the-igniter charge I6, thus completely sealing the thimble' lil, and sealing the perforations Ill. Such means may consist of a rammer Il as shown in Figures 5 and 6. When the head l2 containing the pern cussiony elements is screwed in tight'engagement with screw threads I3, the primer is ready for use in connection with xed, semi-fixed or separate loading ammunition. The striking of the percussion cap or element in the head l2 produces a flame which ignites-the igniter charge of black powder or other igniter charge I6 which has-been placed within the fusible thimble ID. The burni ing of the igniter charge produces flame which meets the fusible thimble and this flame passes to the exterior of the igniter charge tube il tin asa component of the metal thereof, because of the' products resulting from the destruction of the thimble bythe burning of the igniter charge promotes' or causes decoppering of the bore of the cannon.

'Having thus described my invention, I claim:

RFRENCES orrED The following references are of record in the file of this pat-ent: f

UNITED STATES PATENTS Nuirlbr-:rl Name i Date 217,534 l Hunt July 15, 1879 399,879 Graydon Mar. 19, 1869 v 837,958 Dupont Dec. 11, 1906 1,873,202 y Hitt Auges, 1932 1,901,469 Piccard Mahl/l, 1933 1,909,776 Lowy May 16, 1933 2,188,760

Richardson Jan. 30, 1949 

